What Time of Day is Best to Take Ovulation Tests?

by | Aug 8, 2019

If you are trying to conceive, you may have heard about the ovulation tests. They help to find out when you ovulate, so you know the best time to try for a baby. Before you go through the efforts, it is important to make sure you are using them correctly. 

When you are not ovulating, your hormone level is low. Test with the first-morning urine is preferred. 

woman with a clock

LH surge often happens during the day. So you will want to test in the morning and afternoon on the day of ovulation to not miss it. Let’s dive into this!


How does an ovulation test work?

An ovulation test detects the luteinizing hormone or LH surge in the urine to track ovulation. It is also called the ovulation prediction kit, or OPK.

At the beginning of each menstrual cycle, the follicle-stimulating hormone or FSH stimulates multiple ovarian follicles to grow. These ovarian follicles soon increase the production of estrogen, which rises about 4-5 days leading to ovulation. 12-24 hours before ovulation, LH surges sharply and triggers the ovary to release a mature egg. These ovulation kits detect the LH surge in urine to determine if ovulation is about to happen.


How to take an ovulation test?

  • To not miss your fertility peak, you should start testing a few days before the expected ovulation.
  • Continue taking the test once a day until the result is positive.
  • To not dilute the LH concentration, you should use morning urine or limit fluid intake for 2 hours before the test. Excessive fluid intake affects test accuracy.
  • If you see the positive result in the morning, test again in 6 hours. An LH surge often happens during the day.
  • After the first positive result, ovulation usually happens within the next 48 hours.
  • Follow the instructions of the brand you chose. Just like a pregnancy test, a faint second line usually means a negative test result for ovulation.


When should I start testing?

You will want to start early in the menstrual cycle to not miss the ovulation.

You may think you only need to test on the few days around ovulation. The truth is your cycle length and ovulation day can differ from cycle to cycle. For some digital ovulation tests, you will even have to start right after the period to set the hormone baseline.

With Mira, the smart algorithm dynamically calculates when you need to test based on your personal cycle pattern. You will not have to go through the hassle of daily tests or worry about missing your ovulation.

Having a hard time tracking ovulation? Mira takes the guesswork out by measuring your actual fertility hormone concentrations! Sign up today for exclusive Mira content and discounts!
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What is the best time of day to take an ovulation test?

It is best to follow the instructions on the brand of tests you are using.

Some brands require testing with morning urine because of the limited fluid intake and easiness of managing. Other brands recommend afternoon test because the LH surge often shows up in the urine in the afternoon. The LH surge often happens during the day. But it takes a few hours for the hormone to appear in the urine.

The LH surge of some women can last up to a few days. Others may have a surge that lasts only a few hours. Both are fine but it is easier to miss the short surge if you only test in the morning. That is why you may want to test twice on the day of the LH surge.

It is not necessary to test twice on the days other than the day of the LH surge.


How soon after a positive ovulation test do I ovulate?

24-36 hours after the LH surge, ovulation usually happens. LH is a good indicator of ovulation and your peak fertility days. It then decreases sharply. On average, the entire LH surge lasts about 2 days.


How do I take the ovulation test with an irregular cycle?

You should start testing at least 3 days before the expected ovulation. Even if your cycle lasts 28 days, your ovulation day can vary.

For irregular cycles, the best option is to determine your shortest cycle in the past 6 months. Then consider the current cycle as your shortest cycle. Calculate the expected ovulation day based on it and start testing 3 days before that.


How can I never get a positive ovulation test?

There are multiple explanations that why you don’t get a positive ovulation test result:

  • You didn’t use morning urine. LH concentration has been diluted.
  • You have a long or short cycle, or your ovulation happened earlier or later than the expected day. You may have tested too early or missed the ovulation.
  • You have a short LH surge. You may have missed it if you only tested once a day.
  • You have a low LH baseline. The ovulation kits determine your ovulation based on a fixed LH threshold. However, this threshold can be variable for every woman and every cycle. Your ovulation kit gave a false negative result.
  • You didn’t ovulate. You can occasionally miss ovulation for a cycle or two. If this happens to you frequently, seek for doctor’s help.
  • The test was not performed correctly. For example, you didn’t sample enough urine.


Are ovulation test results 100% accurate?

Nope! Inaccurate results can happen for the reasons below:

Your hormone level varies. Using a fixed hormone threshold to determine ovulation doesn’t apply to everyone. Actually, the cycle length and hormone level vary hugely from woman to woman and cycle to cycle. This is why a lot of women had “missed peak” while using an OPK.

Mira’s smart algorithm determines the ovulation based on your personal hormone levels, so you won’t have another “missed peak”.

If you have polycystic ovaries (PCOS), you tend to have elevated LH levels. An OPK will give you positive results all the time but obviously, you are not ovulating. In this case, Mira can track your actual hormone levels and show your unique hormone curve. So you are able to see when ovulation truly happens to you.

You can also monitor the change in your cervical mucus to know better about your body. Basal body temperature can be used to confirm ovulation. But it is not a good method to predict ovulation or help to conceive.

✔️ Medically Reviewed by Dr Roohi Jeelani, MD, FACOG and Lauren Grimm, MA

roohi jeelaniDr Roohi Jeelani is Director of Research and Education at Vios Fertility Institute in Chicago, Illinois. Dr Jeelani earned her medical degree from Ross University School of Medicine in Portsmouth, Dominica. She then completed a residency in Obstetrics and Gynecology and a fellowship in Reproductive Endocrinology and Infertility at Wayne State University, Detroit Medical Center, where she was awarded a Women’s Reproductive Health NIH K12 Research Grant. She is board certified in Obstetrics and Gynecology. Dr Jeelani has authored numerous articles and abstracts in peer-reviewed journals, and presented her research at national and international scientific meetings. A Fellow of the American College of Obstetrics and Gynecology, Dr Jeelani is a member of the American Medical Association, the American Society of Reproductive Medicine, and the American Association of Gynecologic Laparoscopists.

Lauren Grimm is Research Coordinator at Vios Fertility Institute in Chicago, Illinois. Lauren earned her bachelor’s degree from Loyola University Chicago, where she also completed her masters in Medical Sciences. Lauren has worked alongside Dr. Jeelani for the last 3 years, authoring a number of abstracts and articles in peer-reviewed journals, and presented her research at national and international scientific conferences. Lauren will be continuing her education this fall at Rush University Medical College in Chicago, IL as an MD candidate.

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Ready to easily, precisely, and automatically track your ovulation cycles? Let Mira take the guesswork out of getting pregnant, so you know exactly when to conceive.